UUID generators (v4)

Revision 4 of this benchmark created by Jeff Ward on

Setup

function b() { return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function(c) {
      var r = Math.random()*16|0, v = c == 'x' ? r : (r&0x3|0x8);
      return v.toString(16);
  });}
  
  function e1() {
    var u='',i=0;
    while(i++<36) {
      var c='xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'[i-1],r=Math.random()*16|0,v=c=='x'?r:(r&0x3|0x8);
      u+=(c=='-'||c=='4')?c:v.toString(16)
    }
    return u;
  }
  
  function e2() {
    var u='',m='xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx',i=0,rb=Math.random()*0xffffffff|0;
    while(i++<36) {
      var c=m[i-1],r=rb&0xf,v=c=='x'?r:(r&0x3|0x8);
      u+=(c=='-'||c=='4')?c:v.toString(16);rb=i%8==0?Math.random()*0xffffffff|0:rb>>4
    }
    return u
  }
  
  function e3() {
    var l='0123456789abcdef';
    var m='xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx';
    var u='',i=0,rb=Math.random()*0xffffffff|0;
    while(i++<36) {
      var c=m[i-1],r=rb&0xf,v=c=='x'?r:(r&0x3|0x8);
      u+=(c=='-'||c=='4')?c:l[v];rb=i%8==0?Math.random()*0xffffffff|0:rb>>4
    }
    return u
  }
  
  function e4() {
    var h=['0','1','2','3','4','5','6','7','8','9','a','b','c','d','e','f'];
    var k=['x','x','x','x','x','x','x','x','-','x','x','x','x','-','4','x','x','x','-','y','x','x','x','-','x','x','x','x','x','x','x','x','x','x','x','x'];
    var u='',i=0,rb=Math.random()*0xffffffff|0;
    while(i++<36) {
      var c=k[i-1],r=rb&0xf,v=c=='x'?r:(r&0x3|0x8);
      u+=(c=='-'||c=='4')?c:h[v];rb=i%8==0?Math.random()*0xffffffff|0:rb>>4
    }
    return u
  }
  
  var lut = []; for (var i=0; i<256; i++) { lut[i] = (i<16?'0':'')+(i).toString(16); }
  function e5() {
    var k=['x','x','x','x','-','x','x','-','4','x','-','y','x','-','x','x','x','x','x','x'];
    var u='',i=0,rb=Math.random()*0xffffffff|0;
    while(i++<20) {
      var c=k[i-1],r=rb&0xff,v=c=='x'?r:(c=='y'?(r&0x3f|0x80):(r&0xf|0x40));
      u+=(c=='-')?c:lut[v];rb=i%4==0?Math.random()*0xffffffff|0:rb>>8
    }
    return u
  }
  
  function e6() {
    var k=['x','x','-','x','-','4','-','y','-','x','x','x'];
    var u='',i=0,rb=Math.random()*0xffffffff|0;
    while(i++<12) {
      var c=k[i-1],r=rb&0xffff,v=c=='x'?r:(c=='y'?(r&0x3fff|0x8000):(r&0xfff|0x4000));
      u+=(c=='-')?c:(lut[v>>8]+lut[v&0xff]);rb=i&1?rb>>16:Math.random()*0xffffffff|0
    }
    return u
  }
  
  function e7()
      {
      var d0 = Math.random()*0xffffffff|0;
      var d1 = Math.random()*0xffffffff|0;
      var d2 = Math.random()*0xffffffff|0;
      var d3 = Math.random()*0xffffffff|0;
      return lut[d0&0xff]+lut[d0>>8&0xff]+lut[d0>>16&0xff]+lut[d0>>24&0xff]+'-'+
        lut[d1&0xff]+lut[d1>>8&0xff]+'-'+lut[d1>>16&0x0f|0x40]+lut[d1>>24&0xff]+'-'+
        lut[d2&0x3f|0x80]+lut[d2>>8&0xff]+'-'+lut[d2>>16&0xff]+lut[d2>>24&0xff]+
        lut[d3&0xff]+lut[d3>>8&0xff]+lut[d3>>16&0xff]+lut[d3>>24&0xff];
    }
  
  function s4() {
    return Math.floor((1 + Math.random()) * 0x10000)
               .toString(16)
               .substring(1);
  };
  
  function guid() {
    return s4() + s4() + '-' + s4() + '-' + s4() + '-' +
           s4() + '-' + s4() + s4() + s4();
  }
  
  function generateQuickGuid() {
      return Math.random().toString(36).substring(2, 15) +
          Math.random().toString(36).substring(2, 15);
  }

Test runner

Ready to run.

Testing in
TestOps/sec
broofa
b()
ready
e1
e1()
ready
e2
e2()
ready
e3
e3()
ready
e4
e4()
ready
e5
e5()
ready
e6
e6()
ready
generateQuickGuid
generateQuickGuid()
ready
guid_accepted
guid()
ready
e7
e7()
ready

Revisions

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